1. Field of the Invention
The present invention relates to an improved air bag device for use in a vehicle, and more particularly, to an air bag of a vehicle which has an impact transformation opening door system or a lever opening door system for easily and effectively opening an air bag door when the vehicle undergoes an impact.
2. Description of Related Art
Various types of air bag devices for a vehicle are known in the art. Generally, most vehicles include an air bag outer skin disposed within a case which has a door core having a V-shaped tearing groove disposed on a lower connecting plate thereof.
However, the conventional air bag device suffers from a number of problems, such as, for example, the V-shaped tearing groove is very difficult to manufacture in order to have a certain thickness of about 0.4-0.5 mm. It is likely that immediate tearing at the groove may be delayed when a traffic accident occurs so that injury will result to the vehicle occupants, and the conventional device is expensive to manufacture. The difficulty in obtaining and maintaining a groove of the certain thickness correspondingly leads to either opening of the air bag door too early or too late, rather than a repetitively punctual opening of the air bag door.
As shown in FIG. 1, the conventional air bag device is disposed within an air bag mounting portion 20 of a dashboard 10 such as an instrument panel, or an air bag storage area of a steering wheel (not shown). The dashboard 10 includes a gauge panel 15, a defroster 40 and a glove box 30.
As shown in FIG. 2, the conventional air bag device includes an air bag case 130, an air bag outer skin 100 surrounding a circular tube 120 wherein the air bag outer skin 100 and the circular tube 120 are disposed within the air bag case 130, an inflator 110 disposed in the circular tube 120 for supplying a compressed air, and an air bag door 65 united with the case 130. The case 130 is connected to a cross member 50 of a panel of the vehicle (not shown) by a fixing bolt 140 and a nut 145.
The air bag door 65 is composed of a door skin 60 and a plastic door core 70 having an upper connecting plate 158 and a lower connecting plate 85. The upper connecting plate 158 has a plurality of engagement grooves 155 for correspondingly engaging with a plurality of projections 150 supported on an upper wall of the air bag case 130. The lower connecting plate 85 has a plurality of pins 90 for correspondingly engaging with a plurality of apertures 91 disposed on a lower wall of the case 130, and a plurality V-shaped tearing grooves 80 disposed on the outer surface of the lower wall of the case for tearing when a vehicle impact occurs.
Therefore, after the vehicle impact occurs and a detonating fuse 115 is supplied with an electric current, compressed air is supplied interior of the bag outer skin 100 from the inflator 110, the tearing groove 80 tears and the door core 70 is opened outward by detonating power in the direction indicated by an arrow from the closed position to the open position shown in FIG. 2. At this time, the air bag outer skin 100 forms a kind of expanded air bag (not shown).
Thus, the conventional air bag device should have a thickness of 0.4-0.5 mm of the tearing grooves 80 for easily releasing the door 65 from the air bag case 130. However, it is very difficult to repeatedly injection mold a predetermined thickness of the tearing grooves 80, rendering the air bag device expensive to manufacture and inconsistent in operation. Thus, although the conventional air bag devices worked well for their intended purpose in a majority of impacts, it is possible that the tearing grooves 80 will not tear and the bag door will not work upon vehicle impact and may tear too late so that the driver and passengers receive bodily harm.